We look at many different aspects of astrophysical compact objects (neutron stars, pulsars, black holes)
to answer fundamental questions not only about these bizarre objects but also about related physical processes such as cosmic ray production, particle acceleration,
compact binary physics, accretion, and supernova remnant (SNR) evolution. We also to study the entire population
of Galactic X-ray sources (including black holes, microquasars, X-ray binaries).
Neutron stars are collapsed stars whose surfaces can be hot enough to emit radiation in ultraviolet and X-rays.
In addition many neutron stars manifest themselves as pulsars - objects that emit short intense bursts of radio waves, x-rays,
or visible electromagnetic radiation
at regular intervals. Due to the extreme conditions in the neutron star interiors, these objects can be used
as natural laboratories for studying the poorly understood properties of the superdense,
strongly magnetized, superconducting matter. Such conditions can never be reproduced in
Earth laboratories and therefore studying neutron stars provides the only way to learn about
the nuclear reactions and interactions of the elementary particles under these extreme conditions. This information is of fundamental importance for particle and quantum field physics.
Studying pulsar winds allows one to understand the complicated PWN morphologies, elucidate the dynamics of relativistic magnetized outflows and their interaction with the ambient
medium (e.g., host SNR), and learn about particle acceleration in magnetized relativistic plasmas. X-ray and
optical observations of neutron stars provide valuable diagnostics of all these processes.
Microquasars are the most extreme manifestations of stellar black holes. In these system (which are in many respects analogues to their supermassive counterparts in active galactic nuclei)
matter pulled from a massive companion star falls into a black hole or onto a neutron star. In this proccess the matter heats up to very high temperatures and emits intense X-ray radiation.
Due to the rapid rotation of the compact object s fraction of infalling matter is being ejected from the system along the compact object spin axis leading to formation of jets
whose nonthermal emission can be seen througout a wide range of frequencies. Some microquasars are also emit very high energy (VHE) radiation in GeV and TeV bands. The exact mechanism responsible for the VHE radiation is has not yet been established with several
possibilitites being currently explored.
Also learn about ghostly supernova remnants, another product of cosmic explosions!
Research Areas in Compact Object Astrohpysics:
- Pulsars winds and pulsar-wind nebulae;
- Thermal emission from neutron stars;
- Extended TeV sources and pulsar winds;
- Interaction processes in tight relativiestic binaries;
- Modeling of relativistic magnetized outflows;
- Searching galactic surveys for compact objects;
- Searching for nearby, relic neutron stars, trasient magnetars and isolated black holes;
- Radial-velocity searches for non-accreting black holes in binary systems;
- Classifying unidentified X-ray sources from Chandra and XMM-Newton observations;
- AstroStatistics and Machine-Learning in Astronomy
- Modeling observational signatures from pulsars with shut-off pair cascades;
- Modeling properties of emission coming from the vicinity of the BH event horizon.
Graduate students and postdocs trained in my group (more recent first):
- former GW Physics graduate student, Noel Klingler (PhD 2018), now postdoc in the Swift Team at Pennsylvania State University, US
- former GW Physics graduate student, Jeremy Hare (PhD 2018), now postdoc at UC Berkely, US
- former GW Physics postdoc, Dr. Blagoy Rangelov (2013-2016), now Assistant Professor at Texas State University, US
- former UF Astronomy postdoc, Dr. Martin Durant (2008-2012), now data scientist and software engineer at Continuum Analytics
Present and former collaborators (more recent first, the list is always incomplete):
Our group also includes several graduate and undergradue students working on various
projects at George Washington University and Penn State University.
We welcome new students and postdocs willing to work with us in these exiting areas of High-Energy Astrophysics!
Our research is supported by vigorous observing program carried out on nearly all major space observatories (Chandra,
XMM-Newton, Suzaku, HST, Spitzer) as well as Gran Telescopio CANARIAS (Spain),
Very Large Array (New Mexico, US), and Australia Telescope Compact Array. Dr. Kargaltsev is also an associate member of VERITAS collaboration.
- George Pavlov, Pennsylvania State University, US
- Roger Romani, Stanford University, US
- Pat Slane , Harvard University (CfA), US
- Chryssa Kouveliotou, George Washington University, US
- Steve Eikenberry, University of Florida, US
- Thomas Pannuti, Morehead State University, US
- Brian Williams, STScI, US
- Tatiyana Apanasovich , George Washington University, US
- Kalvir Dhuga, George Washington University, US
- Gordon Garmire, Pennsylvania State University, US
- Sangwook Park , University of Texas Arlington, US
- Andrei Bykov , Ioffe Physico-Technical Institute, Russia
- Zdenka Misanovic, Monash University, Australia
- Roberto Mignani, Kepler Institute of Astronomy, Poland
- Koji Mori, University of Miyazaki, Japan
Find out more:
Recent Developments and Selected Publications